Chain saw



M. MERZ CHAIN SAW March 1l, 1952 2 SHEETS--SHEET l Filed July 22, 1947 /Nn/ENTa/e Mmc MERZ Patented Mar. 11, 1952 CHAIN SAW Max Merz, Seattle, Wash., vassigner to Engineering Research, Inc., a corporation of Washington Application July 22, 1947, Serial No. 782,662

.1 Claim. l

iiled on November 1, 1946, under Serial No.

707,112, wherein I disclosed a power saw that is designed for the falling of trees, the bucking of logs and for various other' sawing operations and wherein the sawing element itself was illustrated as comprising a continuous belt of pivotally connected links including cutter links of novel type. located at regularly spaced intervals along the belt, alternately' at opposite sides thereof and designed to cut away the opposite side surfaces and bottom of the kerf.

In order to impart a better understanding of the improvements of the present invention, their objects and advantages, it will here be explained that in the actual use of the saw of the above identiiied application,l there was some difficulty experienced when sawing in hard wood due to a tendency of the cutter carrying links of the saw chain to jack-knife and thereby cause, or tend to cause, the cutters to gouge into the kerf and to stall or cut irregularly; the main objection to this action being that it slowed down the speed of the sawing or cutting operation.

In view ot the above, it has been the principal yobject of this invention to provide improvements,

particularly in the design of certain of the links of the chain, whereby an abutting relationship is obtained between links that had the tendency to buckle or jack-knife, that eliminates or prevents this action and a smoother and speedier cutting operation is made possible.

More specifically stated, the present invention resides in the provision of a saw chain of continuous belt form, adapted for operation along and in guiding contact with opposite edges of a saw blade and about sprocket wheels at the ends of the blade, and which chain is made up of a succession of pivotally joined links, arranged in groups, and wherein the connected groups alternately are equipped with right and left cutters.

Still further objects of the invention are to be found in the details of construction of the various links embodied in the link groups and in the relationship of the cutter links with the abutting links of the chain, as will hereinafter be fully described.

In accomplishing the above mentioned and 'l other objects ofthe invention, I have provided the Himproved details of construction, the preferred forms of which are illustrated in the accompanying drawings, whereine Fig. 1 is a side view of a power saw comprising a saw chain in which the improvements of the present invention are embodied.

Fig. 2 is an enlarged, side view of a portion of the saw chain and a sectional detail of a portion of the chain supporting bar or blade as associated therewith. j

Fig. 3 is an edge view of a part of the saw chain, showing the disposition of the cutter links, relative to those links that come into end to end abutment.

Fig. 4 is an enlarged, cross section taken on the line 4-4 in Fig. 2.

Fig. 5 is an enlarged, cross section taken on the line 5-5 in Fig. 2.

Fig. 6 is a perspective view of the links as embodied in one of the link groups, shown in disconnected relationship for better understanding of details of construction.

Fig. 7 is a side view of a portion of a saw chain of an alternative form of construction.

Referring more in detail to the drawings- The general type of power saw for which the present saw chain is designed for use is shown in Fig. 1 wherein l0 designates a saw blade or bar and II designates a frame to which one end of the bar is secured for the intended use of' the saw. Supported by the frame II is an engine, designated generally by reference numeral l2, that operates through suitable power transmission devices and controls not herein shown, to rotatably drive a sprocket wheel I3 that is located in the frame and in the plane of and adjacent the inner end of the bar I 0. At the outer end of the bar I0,

a handle frame I4 isfxedrigidly thereto and in this frame a sprocket wheel I6 is rotatably mounted in the plane of the bar I0. The chain saw embodied by this invention, designated generally by reference character 5, is of continu ous belt form and extends about the sprocket wheels I3 and I6 and is supported by and guided along the opposite longitudinal edges of the bar I0 as is common and well understood in the art. The bar or blade l0 is formed in each of its opposite longitudinal edges with a square cut channel I1 as shown in Figs. 2, 4 and 5 and in which channels certain parts of some of the links of the chain are designed to travel to guide and functionally support the chain in use, as will presently be explained. ,V `Referring now more particularly to the saw of Figs. 1 to 6 inclusive: The saw cha-in designated 'generally by reference character .S comprises a succession of plvotally joined links, arranged in groups, and the successive link groups also are joined pivotally end to end to make up the continuous saw chain -S.

Each link group, as will be best understood by reference to Fig. 6, comprises one link which I will hereinafter refer to as a spacer lin and designated by reference numeral I8; a link which I will refer to as a depth gauge link, designated by numeral I9., and two "connector links designated respectively by reference numerals .20 and' In the assembly of links in each group,

the links I8 Vand |9 are located end to end in the... plane o f the chain belt. The connector links are located at opposite sides of the links I8 and |971 Y the outside of the blade.

sharpened edge of the blade body extends from which they join and the links in the group are pivotally joined by pivot pins or rivets 2 I. As seen' in Figs. 4 and 5, the pins have roller bushings 22 applied about their medial portions; fitted inholes 23 in the end portions of the spacer anddepth gauge links, and the opposite end portions of the pins are extended through openings 24 in the connector links and have flattened heads-2| 'at their outer ends 'to hold them functionally' in=v place. .Y

As shown in Figs. 2 and 3, the successive groups of link are joined end to end by paired con-v nector links 26-26, and these are alike in sizef/ and shape and are arranged at opposite sides of the links which they directly connect andare pivo'tally joined thereto by'pivotpins 2 Ir like lthe pins 2| above described.

It is shown also in Figs. 2 and 3 that'in thel successive groups of links 'as arranged-'along the chain belt, the connector links -2IJ" are formed integrally with the kerf cutters Z'IR.v and-21L Vwhich* will presently be more fully described;

these cutters being disposed alternately at opposite sides of the chain belt, and are designed as right and "1eft cutters, each to cut anivaijfraV portion of the side andv bottom of the kerf asth chain advances.

In the saw chain as thus assembled, and as shown in Figs. 2 and 3, the spacer links |8'and depth gauge links I9 are arranged alternatelyend to end, in the central plane of thechain, while the paired connector links 26 'and 26 are at oppo'4 site sides of the chain, as also are the connector links 2|) and 20', but these latter alternate, at opposite sides of the chain. The pivot centers of the chain links are all equally spaced.

Formed on the inside edge of'v each offf'th'e spacer links I8 and each of the depth gaugelinks I9, along the trailing end thereof', iis. a flange or wing 30, extendingfin theplane' of the ii-at body portion of the link and adapted for guided travel in the longitudinal-.slots lor channels II." vof the bar I9, asinFgs. 4' and .5,ftof'functi'o'nailyy support and guide the chain' infits travel." 1 'I The connector links'2Il"-2Il" also.2|-'26' in their arrangement atfopposite sides of the chain, are designed for travel .'upon the edge portions of the bar Ill at opposite sides of the bar channels, thus to holdthe outer edges of the guide wings 39 from contact with the bases of .the channels and also to add to the stability of the chain saw in making a cut, as will be understoo by reference to Figs. 4 and. 5.

4lllachof the depth gauge linksv I9 isfOrmed at its outer edge, and substantially Vmidi-way between its ends, with an outwardly extended leg or runner 32, which is designed to engage .with

V alike except as to their being made in .rights-f and lefts and arranged alternately at rightand left side of the chain. Each cutter is integral with the body of the carrying link and comprises a blade or cutter body of a substantial length, and extending lengthwise of the link and extending beyond its outer edge. As seen in end view in Figs. 4 and 5, the cutters 20L and 2I|R are substantially of semi-cylindrical form, and terminate at their lower longitudinal edges in the central, longitudinal plane of the chain.

At their forward ends, the cutters are beveled inwardly, each to a sharpened cutting edge 35, Aand the bevel is such that the cutting edge is at Also, the forward,

the line of the juncture of the blade and link body in a spiral direction, leading toward the inclined rearwardly and has a planing action.

It may be explained further that the bottom edge of each cutter is sloped to provide a slight angle of rake as seen in Fig. 2. Also, a similar angle of rake may be provided at the side of the cutter; l

'In so far as the cutters themselves are concerned, the construction and arrangementis substantially like that disclosedin my previously mentioned co-pending application.

A feature of this invention resides 1n the provision for an abutting relationship of. those links I8 and I9 which are in .the 'same link group, while traveling along the sides of the blade I0. This provision of an abutting relationship is to eliminate the jack-kning tendency or effect that in my previous design sometimes resulted from sawing hard wood, and it is accomplished as fola lows:` Y l `The rear end edge of each depth gauge link I9 is formed at the outside of the line of pivot pins, designated by line p-p on link I9 in Figc,

with a flat edge surface |9:r that is also perpendicular to the said line. Likewise, the forward end edge of the next following spacer link I8 is formed with a flat end surface l8r. When the chainis traveling along the bar, in cutting position, these flat end surfaces'come flatly together asin Fig. 2.

Thus it will be understood that with the chain: advancing in the kerf in the direction indicated bythearrow adjacent thereto in Fig.' 2, therewill bel a tendency of the -cutter equipped connector links 20' to pivot about their' connections with the next adjacent links, but this result is preventedfdue to the abutting contact fof the link end .surfaces which, in effect, providesa rigid infiterlock.

In the modified form of construction showrrinv Figl, .the 'spacer links IIB, which correspond to links I8 of the chain of Fig. 2, have downwardly extending shoulders |25 at their rear ends, and have forwardly and outwardly beveled end sur'- faces |25 at their forward ends. The depth gauge. i

links ||9, Which correspond to links I9 of the chain of Fig. 2, have depth gauge runners |30 at their forward ends against which the shoulders |20 of the next forward link may abut as do the surfaces |89: and |9:c of the links I8 and I9. Also.

Ieach link IIS has a beveled rear end surface |32 adapted to engage against the beveled forward end surface |25 of the next following link, thus to `effect an abutting relationship that gives rigidity to the chain linkage when the lchain is passing along the edge of the blade I0 and pre- 5 vents the jack-kning of links of the chain that might be due to cutting in hard wood.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent, is:

In a power saw of the character described, in combination, a saw guide bar having a chain guide channel formed in a longitudinal edge thereof and a saw chain arranged to travel on the channeled edge of said bar; said chain comprising a succession of pivotally joined like link groups, each link group comprising a forward link equipped at its outer edge medially of its ends with a depth gauge runner and at its opposite edge with a wing for guided travel in the bar channel, a rearward spacer link formed at its outer edge with a wing for guided travel in the bar channel, complemental connector links disposed at opposite sides of the chain for sliding contact upon the edge of said guide bar, and pivot members extended through their ends and pivotally connecting the said forward and rearward links of the group in end-to-end relationship; said forward link and said rearward spacer link having adjacent end surfaces at the outside of and formed at an angle to the line of pivot members to engage in solid abutment while the chain is traveling along said longitudinal edge of the guide bar, one of the connector links having a kerf cutting blade formed ias an integral part thereof and extended beyondrthe abutting surfaces of said forward and rearward links.

MAX MERZ.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED s TATEs@ PATENTS Number Name Date 279,781 Magaw June 1'9, 1883 485,503 Lewis Nov. 1, 1892 815,256 Bible et al. Mar. 13, 1906 1,387,605 Meyer Aug. 16, 1921 1,634,645 Bens July 5, 1927 1,652,295 Bens Dec. 13, 1927 2,326,854 Hassler Aug. 17, 1943 2,351,112 Day June 13, 1944 2,351,738 Blum f June 20, 1944 FOREIGN-PATENTS Number Countryf` Date 593,463 Germany Feb. 27, 1934 

